This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. his workshop will cover theory and practice for the design and simulation of models focused on diffusion-reaction systems such as neurotransmission, signaling cascades, and other forms of biochemical networks (e.g., Coggan et al., 2005, Science 309:446-451;He et al., 2006, Nature 444:102-105). Current versions of the MCell/DReAMM simulation environment (www.mcell.psc.edu and www.mcell.cnl.salk.edu) will be introduced, including new Monte Carlo methods for 3-D simulation of reactions in solution and on arbitrarily shaped biological surfaces, as well as new tools for model design and visualization. Models created from both anatomical reconstruction tools and computer-aided design tools will be covered. Based on feedback from a similar highly successful workshop in June 2006, this workshop has been extended to five full days, and attendees will be strongly encouraged to bring ideas/data for their own simulation projects. The daily schedule will include theoretical and practical lectures, instructor-guided hands-on tutorials, and opportunities for one-on-one interaction with the instructors on individual project development. The primary instructors will be Joel Stiles (National Resource for Biomedical Supercomputing) and Thomas Bartol (Computational Neurobiology Laboratory, The Salk Institute), the original developers of MCell and DReAMM.